Copepoda. 37 
Such oceanic boundary-areas, where warm and cold currents 
meet are interesting both from the biological and the hydro- 
graphical point of view. There are scarcely many places in the 
oceans of the world, where heterogeneous species are so interming- 
Jed as in the North Atlantic. Northern and southern forms are 
here found mixed together, and it is also astonishing to see how 
many new species have been described in later years from the 
North Atlantic slope. During the Irish Fisheries investigations 
especially, under the guidance of dr. £.w.t.HoLt, a multitude of 
the new forms have been brought to light. It will be a task of 
great importance to study the distributions of the new species 
and their relationship to species previously known. One of the 
present writers NORDGAARD, has, in a paper on »Bryozoa from 
the arctic regions, to be printed in »Tromsø museums aarshei- 
ter», hinted at the possibility of the boundery-areas being centres 
of species-building. If so, such areas will also be centres of dis- 
tribution. | 
The preceding considerations are based upon the conception 
of an intimate connexion between currents and planktonic ani- 
mals. Thus the copepods, for instance, may be regarded as indi- 
cators of currents. This theory was partially contradicted by pamas 
et KOEFOED) in a work from 1909. As the question has been 
discussed in a previous paper’), we shall not go further into it here. 
